SISSA Colloquium returns on Monday, October 20th, at 2 PM in Aula Magna Budinich. This time, we will have the pleasure of hosting Professor Gábor Tamás (University of Szeged, Hungary) who will deliver a lecture titled
Similarities and differences of human and rodent neocortical synapses, neurons and networks
Abstract: Experiments on animal models showed that the efficacy of chemical transmission between neurons depends on several factors including the number, spatial distribution and size of synapses, presynaptic release mechanisms, postsynaptic membrane properties and synaptic plasticity. Recordings from human synaptic connections indicated species related differences in synaptic properties leading to altered signal propagation in human cortical microcircuits compared to animal models. The presentation will elucidate quantal and structural differences of human and rat neocortical synapses mechanistically explaining why single neurons of the human neocortex can trigger downstream Hebbian assemblies in local networks. In turn, experiments will be presented from freely behaving animals and humans detecting network episodes and the corresponding firing of identified interneurons and pyramidal cells during defined epochs. The suggestion that evolutionally conserved network episodes could be differentially recruited in mammalian species will be discussed.
Gábor Tamás is a Professor of Neuroscience at the University of Szeged, Hungary, and a member of the Academia Europaea and the Hungarian Academy of Sciences. He began his neuroscience career at the University of Oxford, in the laboratory of Profs. Peter Somogyi and Eberhard Buhl, where he studied the properties of synaptic connectivity between neocortical neurons and described autapses, synapses formed by a neuron onto itself. At Szeged, he established a lab combining electrophysiology and neuroanatomy to study the interactions between cortical neurons and he identified mechanisms that synchronize neurons at gamma frequencies. In collaboration with Prof. Rafael Yuste (Columbia University), by combining two-photon and high-speed confocal imaging, he revealed that interneuron dendrites are organized in calcium microdomains which isolate individual synapses. He built a library of over 15,000 functionally connected neocortical neuron pairs, enabling the study of rare cell types. This work led to the discovery of the neurogliaform cell, the first interneuron type shown to mediate slow GABAB receptor inhibition, and showed that axo-axonic cells, traditionally considered inhibitory, can also act as strong excitatory neurons. His current research focuses on identified microcircuits in behaving humans and unraveling the elementary mechanisms underlying cortical information processing.